Numerical modelling on vibroflotation soil improvement techniques using a densification constitutive law

The densification phenomenon in dry or completely drained sands mainly occurs when these materials are subjected to dynamic loadings. This fact induces a reduction of voids volume and consequently the compaction of the soil. The Generalized Endochronic densification law, formulated in cylindrical coordinates, has been used in a finite element model for simulating vibroflotation soil improvement techniques. The effects of vibrations at a point inside the soil mass, like those applied in vibroflotation treatment, are reproduced with this code. Absorbing boundary conditions are established at those borders where spatial domain finishes, aiming to avoid spurious, artificial reflections of stress waves, which otherwise come into the domain, disturbing the computed results. A mean densification function is defined for each spatial domain, to evaluate the effect of this technique, and also employed to optimize the distance between vibration points. This is a new rational design approach, which represents a step forward development if it is compared with the usual empirical employed procedures